Project description:The process of calcium carbonate biomineralization has arisen multiple times during metazoan evolution. In the phylum Cnidaria, biomineralization has mostly been studied in the subclass Hexacorallia (i.e. stony corals) in comparison to the subclass Octocorallia (i.e. red corals); the two diverged approximately 600 million years ago. The precious Mediterranean red coral, Corallium rubrum, is an octocorallian species, which produces two distinct high-magnesium calcite biominerals, the axial skeleton and the sclerites. In order to gain insight into the red coral biomineralization process and cnidarian biomineralization evolution, we studied the protein repertoire forming the organic matrix (OM) of its two biominerals. We combined High-Resolution Mass Spectrometry and transcriptome analysis to study the OM composition of the axial skeleton and the sclerites. We identified a total of 102 OM proteins, 52 are shared between the two red coral biominerals with scleritin being the most abundant protein in each fraction. Contrary to reef building corals, the red coral is collagen-rich (10 collagen-like proteins). Agrin-like glycoproteins and proteins with sugar-binding domains are also predominant. Twenty-seven and 23 proteins were uniquely assigned to the axial skeleton and the sclerites, respectively. Their inferred regulatory function suggests that the difference between the two biominerals rather relies on the modeling of the matrix network than on specific structural components. At least one OM component appears to have been horizontally transferred from prokaryotes early during Octocorallia evolution. Our results support the view that calcification of the red coral axial skeleton likely represents a secondary calcification of an ancestral gorgonian horny axis. In addition, the comparison with stony coral skeletomes highlighted the low proportion of similar proteins between the biomineral OMs of hexacorallian and octocorallian corals, suggesting an independent acquisition of calcification in anthozoans.
Project description:BackgroundThe impact of global climate change on plant distribution, speciation and extinction is of current concern. Examining species climatic preferences via bioclimatic niche modelling is a key tool to study this impact. There is an established link between bioclimatic niche models and phylogenetic diversification. A next step is to examine future distribution predictions from a phylogenetic perspective. We present such a study using Cyclamen (Myrsinaceae), a group which demonstrates morphological and phenological adaptations to its seasonal Mediterranean-type climate. How will the predicted climate change affect future distribution of this popular genus of garden plants?ResultsWe demonstrate phylogenetic structure for some climatic characteristics, and show that most Cyclamen have distinct climatic niches, with the exception of several wide-ranging, geographically expansive, species. We reconstruct climate preferences for hypothetical ancestral Cyclamen. The ancestral Cyclamen lineage has a preference for the seasonal Mediterranean climate characteristic of dry summers and wet winters. Future bioclimatic niches, based on BIOCLIM and Maxent models, are examined with reference to a future climate scenario for the 2050s. Over the next 50 years we predict a northward shift in the area of climatic suitability, with many areas of current distribution becoming climatically unsuitable. The area of climatic suitability for every Cyclamen species is predicted to decrease. For many species, there may be no areas with a suitable climate regardless of dispersal ability, these species are considered to be at high risk of extinction. This risk is examined from a phylogenetic perspective.ConclusionExamining bioclimatic niches from a phylogenetic perspective permits novel interpretations of these models. In particular, reconstruction of ancestral niches can provide testable hypothesis about the historical development of lineages. In the future we can expect a northwards shift in climatic suitability for the genus Cyclamen. If this proves to be the case then dispersal is the best chance of survival, which seems highly unlikely for ant-dispersed Cyclamen. Human-assisted establishment of Cyclamen species well outside their native ranges offers hope and could provide the only means of dispersal to potentially suitable future environments. Even without human intervention the phylogenetic perspective demonstrates that major lineages could survive climate change even if many species are lost.
Project description:Scleractinian corals acquire autotrophic nutrients via the photosynthetic activity of their symbionts and the subsequent transfer of photosynthates. Zooplankton predation by the animal (heterotrophy) is an additional food source. Under stress events, corals loose their symbionts, a phenomena known as bleaching, which eventually leads to starvation, unless corals increase their heterotrophic capacities. Molecular mechanisms by which heterotrophy sustains metabolism in stressed corals remain elusive. Here for the first time, we identify specific genes expressed in heterotrophically fed and unfed corals maintained under normal and light-stress conditions inducing bleaching. Physiological parameters and gene expression profiling showed ominously that fed corals better resisted the stress than unfed corals, by presenting less oxidative damage and protein/DNA degradation. Light stressed and unfed/starved corals (HLS) up-regulated by 140 and 13 times two genes (CP2U1 and CP1A2), which belong to the Cytochrome P450 superfamily, while these genes remained almost unchanged in fed corals (HLF). Other genes of redox regulation, DNA damage response, molecular chaperones, and protein degradation were also up-regulated in HLS corals, presenting higher bleaching, and strong decrease of the photosynthesis performance compared to HLF corals. Several pivotal genes associated with the calcification apparatus such as carbonic anhydrases, calcium-transporting ATPase, calcium channel subunit, and bone morphogenetic proteins (BMPs), were significantly down-regulated only in HLS corals. A parallel decrease in the calcification rates of these later corals was also observed. All together, these results show clearly that heterotrophy helps preventing oxidative stress in corals, and thus avoid the cascade of metabolic problems downstream this stress.
Project description:Many crop species have complex genomes, making the conventional pathway to associating molecular markers with trait variation, which includes genome sequencing, both expensive and time-consuming. We used a streamlined approach to rapidly develop a genomics platform for hexaploid wheat based on the inferred order of expressed sequences. This involved assembly of the transcriptomes for the progenitor genomes of bread wheat, the development of a genetic linkage map comprising 9495 mapped transcriptome-based SNP markers, use of this map to rearrange the genome sequence of Brachypodium distachyon into pseudomolecules representative of the genome organization of wheat and sequence similarity-based mapping onto this resource of the transcriptome assemblies. To demonstrate that this approximation of gene order in wheat is appropriate to underpin association genetics analysis, we undertook Associative Transcriptomics for straw biomass traits, identifying associations and even candidate genes for height, weight and width.
Project description:Groupers (Epinephelidae) are ecologically, commercially, and culturally important predatory fishes throughout their global distribution range in tropical, subtropical and occasionally temperate regions. They are key species for modern and ancient fisheries in the Mediterranean which have been heavily overfished in the past century leading to smaller catch sizes, lower CPUE, and decreased biomass. There are four species of grouper native to the Mediterranean within the Epinephelus genus.The abundance and distribution of grouper species prior to the 20th century in the Mediterranean remains poorly known. Using peptide mass fingerprinting, also known as Zooarchaeology by Mass Spectrometry (ZooMS), we investigated if ZooMS is a viable method for identifying intra-genus grouper bones to species level. Due to the lack of publicly available genomic sequences and for validation of ZooMS markers, we reconstructed collagen type I amino acid sequences using LC-MS/MS for four Epinephelus spp. Adequate variation between collagen sequences enabled the production of the best supported phylogenetic tree for Mediterranean Epinephelus spp. to date. We identified 23 previously undescribed ZooMS biomarkers capable of distinguishing groupers to the species level. Our novel biomarkers were applied to a case study of 23 grouper/comber fish bones from the Middle to Late Holocene archaeological site of Kinet Höyük, located along the coast of Iskenderun Bay, Turkey. ZooMS markers enabled species level identification of 19 bones with 18 identified as Epinephelus aeneus and 1 identified as Epinephelus marginatus. Combining ZooMS identifications with catch size reconstructions has revealed that E. aeneus is capable of growing ca. 30 cm larger than previously reported. This abundance and dominance of E. aeneus locally at Kinet Höyük is consistent with E. aeneus being the most prevalent grouper species in Iskenderun Bay today, testifying to several millennia of this species local population persistence despite fishing pressure, habitat degradation, and climatic changes.
Project description:RNASeq data on corals transplanted reciprocally into two different thermal microhabitats on Ofu Island Six individual corals transplanted into two habitats
Project description:Diet can regulate gene and microRNA (miRNA) expression and various biological processes in the gut. Dietary interventions have been proposed as therapeutic approaches for several diseases, including cancer. In a pilot study, we showed that a low-inflammatory Mediterranean diet reduced markers of local and systemic inflammation in 27 patients with Familial Adenomatous Polyposis (FAP). We evaluated the changes induced by a low-inflammatory Mediterranean dietary intervention on fecal miRNome and intestinal tissue transcriptome in FAP subjects and assessed whether these changes could be associated with the beneficial effects observed in the pilot study. The diet modulated 41 fecal miRNAs, and this modulation remained for three months after the intervention. miR-5092-5p, miR-4527, and miR-3612-3p were positively correlated with adherence to the Mediterranean diet, while miR-6867-5p and miR-760-5p were negatively correlated with serum calprotectin levels. The altered miRNAs target genes mainly related to inflammatory pathways, DNA repair, metabolism, and cytoskeleton organization. Seventy genes were differentially expressed between adenoma and normal tissue. Most were different before the dietary intervention, but reached similar levels after the diet. Functional enrichment analysis identified the proinflammatory ERK1/2, cell cycle regulation and nutrient response pathways as commonly regulated by differentially expressed miRNAs and genes. These findings suggest that fecal miRNAs modulated by the diet reflect an epigenetic regulation occurring in tissues that seems to influence inflammatory pathways. miRNAs and genes with oncogenic and tumor suppressor functions are also regulated, highlighting the potential cancer-preventive effect of the low-inflammatory Mediterranean diet.
Project description:Reduced levels of trienoic fatty acids (TAs) in chloroplast membranes induce thermotolerance in several plant species, but the underlying mechanisms remain unclear. TA peroxidation in plant cell membranes generates cytotoxic, TA-derived compounds containing ?,?-unsaturated carbonyl groups. The relationship between low TA levels and the amounts of cytotoxic TA-derived compounds was examined using thermotolerant transgenic cyclamen (Cyclamen persicum Mill.) with low TA contents. Changes in the levels of the cytotoxic TA-derived acrolein (ACR), methyl vinyl ketone (MVK), (E)-2-hexenal, 4-hydroxy-2-nonenal, and malondialdehyde were analysed in the leaf tissues of wild-type (WT) and thermotolerant transgenic cyclamen under heat stress. Levels of ACR and MVK in the WT increased in parallel with the occurrence of heat-induced tissue damage, whereas no such changes were observed in the thermotolerant transgenic lines. Furthermore, exogenous ACR and MVK infiltrated into leaves to concentrations similar to those observed in heat-stressed WT leaves caused similar disease symptoms. These results suggest that thermotolerance in transgenic cyclamen depends on reduced production rates of ACR and MVK under heat stress, due to the low level of TAs in these plants.
| S-EPMC3398453 | biostudies-literature
Project description:2bRAD sequences of shallow and mesophotic Montastraea cavernosa corals